Enhancement of renal carcinogenicity by combined inhalation and oral exposures to chloroform in male rats

Nagano, K; Kano, H; Arito, H; Yamamoto, S; Matsushima, T

HERO ID

1066672

Reference Type

Journal Article

Year

2006

Language

English

PMID

16952903

HERO ID 1066672
In Press No
Year 2006
Title Enhancement of renal carcinogenicity by combined inhalation and oral exposures to chloroform in male rats
Authors Nagano, K; Kano, H; Arito, H; Yamamoto, S; Matsushima, T
Journal Journal of Toxicology and Environmental Health, Part A: Current Issues
Volume 69
Issue 20
Page Numbers 1827-1842
Abstract Chloroform, ubiquitously present in indoor and outdoor air, drinking water, and some foodstuffs, enters the human body by inhalation, oral and dermal routes of exposure. In order to provide bioassay data for risk assessment of humans exposed to chloroform by multiple routes, effects of combined inhalation and oral exposures to chloroform on carcinogenicity and chronic toxicity in male F344 rats were examined. A group of 50 male rats was exposed by inhalation to 0 (clean air), 25, 50, or 100 ppm (v/v) of chloroform vapor-containing air for 6 h/d and 5 d/wk during a 104 w period, and each inhalation group was given chloroform-formulated drinking water (1000 ppm w/w) or vehicle water for 104 wk, ad libitum. Renal-cell adenomas and carcinomas and atypical renal-tubule hyperplasias were increased in the combined inhalation and oral exposure groups, but not in the oral- or inhalation-alone groups. Incidences of cytoplasmic basophilia and dilated tubular lumens in the kidney, as well as incidence of positive urinary glucose, were markedly increased by the combined exposures, compared with those after single-route exposures. It was concluded that combined inhalation and oral exposures markedly enhanced carcinogenicity and chronic toxicity in the proximal tubule of male rat kidneys, suggesting that carcinogenic and toxic effects of the combined exposures on the kidneys were greater than the ones that would be expected under an assumption that the two effects of single route exposures through inhalation and drinking were additive.
Doi 10.1080/15287390600630146
Pmid 16952903
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Is Qa No